How to check for presence of 'key' in jq before iterating over the values

Question

I get Cannot iterate over null (null) from the below query because .property_history is not present in result object.

How do i che

Answer 1

You can use the select-expression in jq to do what you intend to achieve, something as,

jq '.result | select(.property_history != null) | .property_history | map(select(.event_name == "Sold"))[0].date'
"08/30/2004"

Answer 2

You could use the ? post-fix operator:

$ jq '.result 
  | .property_history? 
  | .[]
  | select(.event_name == "Sold") 
  | .date'
"08/30/2004"

Answer 3

jq '.result.property_history // empty | map(select(.event_name == "Sold"))[0:1][].date'`

Trick is to use // together with empty.

Another alternative is to use an additional select:

jq '.result.property_history | select(.) | map(select(.event_name == "Sold"))[0:1][].date'`